Electrolysis cell with vertical bipolar electrodes

ABSTRACT

An electrolyser of the series connected filter press type with vertical bipolar electrodes for the production of chlorine, hydrogen and caustic alkali by the electrolysis of a solution of an alkali metal chloride comprises a series of elementary electrolysis cells surmounted by a tank containing the solution. Each of the elementary cells is in communication with the tank by an individual duct of insulating material which extends approximately over the entire height of the cell and opens into the anode chamber at the bottom of the cell. A duct for the evaculation of chlorine from each cell passes up through the bottom of the tank and extends up inside the tank to a point above the level of the solution. Duct means are formed in the bottom portion of the cell frame members, with one duct means registering with a U-shaped tube in each cell for withdrawing caustic alkali from the cell, a second duct means registering with a tube extending to the upper part in each cell for withdrawing hydrogen from each cell, and with a third duct means registering with a transverse distributor in each cell for supplying reagent to each cell.

United States Patent [1 1 Giacopelli ELECTROLYSIS CELL WITH VERTICALBIPOLAR ELECTRODES Umberto Giacopelli, Solvay, Leghorn, Italy {73]Assignee: Solvay & Cie, Belgium 422) Filed: Dec. 26, 1972 [2|] Appl. No:318,640

{44] Published under the Trial Voluntary Protest Program on January 28,l975 as document no.

[75] Inventor:

0} Foreign Application Priority Data Dec. 23, 1971 Belgium H2096 m2] US.Cl. 204/256; 204/255; 204/257; 204/258; 204/269; 204/270 -l] Int. Cl. .rC25B 13/00 1! Field of Search 204/255, 256, 257, 258,

ml References Cited UNITED STATES PATENTS [ll] B 3,925,186

l l Dec. 9, 1975 Primary Examinerlohn H. Mack Assistant Examiner-W. l.Solomon Attorney, Agent, or FirmRobert E. Burns; Emmanuel J. Lobato;Bruce L. Adams 57 ABSTRACT An electrolyser of the series connectedfilter press type with vertical bipolar electrodes for the production ofchlorine, hydrogen and caustic alkali by the electrolysis of a solutionof an alkali metal chloride comprises a series of elementaryelectrolysis cells surmounted by a tank containing the solution Each ofthe elementary cells is in communication with the tank by an individualduct of insulating material which at' tends approximately over theentire height of the cell and opens into the anode chamber at the bottomof the cell. A duct for the evaculation of chlorine from each cellpasses up through the bottom of the tank and extends up inside the tankto a point above the level of the solution. Duct means are formed in thebottom portion of the cell frame members with one duct means registeringwith a U-shaped tube in each cell for withdrawing caustic alkali fromthe cell, a sec ond duct means registering with a tube extending to theupper part in each cell for withdrawing hydrogen from each cell, andwith a third duct means registering with a transverse distributor ineach cell for supplying reagent to each cell.

3 Claims. 8 Drawing Figures US. Patent Dec. 9, 1975 Sheet 1 of83,925,186

FIG. I

U.S. Patent Dec. 9, 1975 Sheet 2 of8 3,925,186

FIG. 2

US. Patent Dec. 9, 1975 Sheet 3 of8 FIG. 3

J ////fi////////////// v r h v 4 d 4 I U.S. Patent Dec. 9, 1975 Sheet 4of8 3,925,186

U.S. Patfint Dec. 9, 1975 Sheet 5 of8 3,925,186

US. Patent Dec. 9, 1975 Sheet 6 of8 3,925,186

FIG. 6'

U.S. Patent Dec. 9, 1975 Sheet 7 of8 3,925,186

FIG. 7

mv -r10 U.S. Patent Dec. 9, 1975 Sheet 8 of8 3,925,186

FIG. 8

k I J f 111 N ELECTROLYSIS CELL WITH VERTICAL BIPOLAR ELECTRODES Theinvention relates more particularly to an electrol0 lyser of thediaphragm type comprising a number of elementary cells with verticalbipolar electrodes connected in series to a source of direct current.

In known electrolysers of this type the elementary cells are fedindividually with electrolyte from a tank arranged above the elementarycells.

In these electrolysers of the series type it is important to reduce toas low a value as possible the electric current branched through theelectrolyte contained in the tank. In order to increase the electricalresistance of this branched circuit it is known that one can divide thetank into the same number of compartments as there are elementary cells,using transverse partitions drilled with apertures of smallcross-section aimed at maintaining the electrolyte at the same level inall the compartments. An electrolyser of this type is described, forexample, in US. Pat. No. 2,282,058 filed in the name of HUNTER et al. onthe Jan. 24, 1939.

A disadvantage of these known electrolysers with a partitioned tankresides in fact in the necessity of arranging partitions in this tank,which is of such a nature as to increase its weight and reduce itsuseful capacity.

Furthermore, the small cross-section of the orifices made in thepartitions of the tank makes it necessary to feed this tank withelectrolyte simultaneously in a number of the compartments of this tankif one wishes to avoid a variation in the concentration of theelectrolyte between these compartments.

The invention overcomes these drawbacks. It relates for this purpose toa diaphragm electrolyser of the series type with vertical bipolarelectrodes for the production of chlorine, hydrogen and a caustic alkaliby the electrolysis of a solution of an alkali metal chloride. Theelectrolyser comprises at least two elementary electrolysis cellssurmounted by a tank containing the solution, each elementary cell beingconnected with the tank and comprising separate ducts for the evacuationof the chlorine, the hydrogen and the caustic alkali. According to theinvention, the electrolyser is characterised by the fact that eachelementary cell is connected with the tank by an individual pipe ofinsulating material which extends approximately over the entire heightof the cell and which leads out near the bottom or into the bottom ofthe latter, and by the fact that the pipe for evacuating the chlorinefrom each elementary cell passes through the bottom of the tank andleads out into a pipe extending up inside the tank to a point above thelevel of the solution.

In the electrolyser according to the invention, the electric circuit ofthe current branched through the electrolyte contained in the tankcomprises the abovementioned pipes connecting this tank with theelementary cells. These pipes extend approximately over the entireheight of these bipolar elements, this branched circuit has a highelectrical resistance so that it is possible in the electrolyseraccording to the invention to do away with the above-mentionedpartitions with which the tank of known cells is equipped.

Furthermore, in the electrolyser according to the invention the anolyteis subjected to an ascending movement in the elementary cells, whichadvantageously facilitates the evacuation of the chlorine discharged atthe anodes.

In the electrolyser according to the invention the chlorine dischargedat the anodes does not percolate through the considerable mass ofelectrolyte contained in the tank, which facilitates its evacuation fromthe elementary cells and, all other things being equal, permits ofhigher current densities. The upper part of the tank constitutes also apocket of high capacity where the chlorine produced in the differentelementary cells accumulates, which is of such a nature as to facilitateits extraction from the electrolyser. According to a particularlyadvantageous form of embodiment, the electrolyser according to theinvention is of the filter press type and formed by the juxtaposition ofa series of frames constituting the lateral walls of the elementarycells According to the invention, the tank is bounded between apartition fitted in a waterproof manner on the whole of the frames and alid in the form of a bell of large dimensions placed on this partition.The partition is drilled on one side with a first series of apertureswhich communicate with the above-mentioned pipes for the admission ofthe solution arranged in the frames, and on the other hand with a secondseries of apertures which communicate with the anode chambers of theelementary cells so as to ensure the evacuation of the chlorine producedin these cells. According to the invention, the latter apertures eachlead out into a distinct tube or in a group into a common tube, thistube being fixed transversely to the partition and emerging above thelevel of the solution in the tank.

As a variant, the tubes may be replaced by a single duct fixedtransversely to the partition, around the above-mentioned second seriesof apertures, and emerging above the level of the solution in the tank.

Particular features and details of the invention will be seen from thedescription which follows of the attached drawings which represent, byway of examples and without restricting the scope of the invention, afew forms of embodiment of the electrolyser according to the invention.

FIG. 1 shows in perspective, with a partial cut-away, a first form ofembodiment of the electrolyser according to the invention.

FIG. 2 shows in horizontal transverse section an elementary cell of theelectrolyser of FIG. 1.

FIG. 3 is a section along the line Ill-Ill of FIG. 2.

FIG. 4 shows a perspective of a second form of embodiment of theelectrolyser according to the invention.

FIG. 5 shows in horizontal transverse section an elementary cell of theelectrolyser of FIG. 4.

FIG. 6 is a section along the plane VI-VI of FIG. 5, with partialcut-away.

FIG. 7 shows partly in elevation a particular form of embodiment of aframe surrounding the cathode chamber of an elementary cell of anelectrolyser of the filter press type in accordance with the invention.

FIG. 8 shows partially in elevation a frame surrounding the anodechamber of the elementary cell of FIG. 7.

In these figures the same reference numbers designate identicalelements.

The electrolyser according to the invention, shown diagrammatically inFIG. 1, is of the series connected filter press type. It comprises anumber of elementary 3 cells 1 with bipolar electrodes, arranged betweentwo end elements 2 and 3 which are anodic and cathodic respectively, andconnected in series with a source of direct voltage which is not shownin the drawing. Crosspieces 4 and tie-rods 5 hold the whole together.

A partition 6 of insulating material covers the whole assembly of theelementary cells 1, and a lid in the form of a bell is placed in a fluidtight manner on the partition 6. The partition 6 and the lid 7 form atank of large capacity for the electrolyte, in this case a sodiumchloride brine. An inlet pipe 8 for supplying electrolyte into this tankis connected to the upper part of the lid 7 and a level indicator 9makes it possible to check the amount of electrolyte in the tank.

An elementary cell 1 of the electrolyser of FIG. 1 is shown in greaterdetail in FIGS. 2 and 3.

This elementary cell comprises a rectangular frame 10 made of steeladjoining a rectangular frame 20 made of a material which does notconduct electricity. The frame 10 serves as a support for an anode 12and a perforated cathode I1 consisting for example of a wire mesh or anexpanded steel plate. The anode 12 may consist of a graphite plate or aplate of a metal of the titanium group, the active surface of which,facing the outside, is covered at least partially by a layer comprisinga metal or a compound of a metal of the platinum group. The cathode 11is covered on its outer surface by a diaphragm not shown in the drawing.Advantageously, in a manner not shown in the attached drawings, theelectrodes may be corrugated so as to increase their surface area. Thecathode 11 and the anode 12 may be provided with metal struts 13.

The chamber 14 bounded between the cathode 11, the anode l2 and theframe 10 constitute the cathode chamber 14 of the elementary cell. Theanode chamber 15 of the elementary cell is bounded between the anode 12,the frame and the cathode ll of an adjacent elementary cell 1.

Apertures l6, l7 and 18 are arranged through the frames 10 and 20 so asto provide for the evacuation of the products of the electrolysis:chlorine, hydrogen and caustic brine respectively.

According to the invention, a pipe 19 for the admission of electrolyteinto the anode chamber 15 is arranged in one of the vertical walls 200of the frame 20. This pipe 19 extends over the entire height of theframe 20 and leads out through an opening 19a in the bottom wall 20b ofthe frame 20 into the bottom 22 of the anode chamber 15. It communicatesin its upper part with an aperture 21 (FIG. 1) arranged through thepartition 6 and leading into the tank containing the electrolyte.

The partition 6 is also drilled with apertures registering with theapertures 16 for the evacuation of the chlorine, and carries tubes 23 inextension of these apertures. These tubes 23 lead out to the inside ofthe above-mentioned tank, under the lid 7, above the level of theelectrolyte. An aperture 38 arranged in the top of the lid 7 providesfor the evacuation of the chlorine produced in the elementary cells 1and collected under the lid 7.

As a variant, the tubes 23 may be fixed directly to the frames 20 in theextension of the apertures 16, which makes it possible to do away withthe partition 6. In this event the upper walls of the frames 10 and 20form the bottom of the electrolyte tank. With such construction, theframes 10, like the frames 20, are preferably made of insulatingmaterial or an insulating layer is provided on the top of each frame 10.However, the use of the partition 6 is advantageous in the case of afilter press cell, in that it avoids any possible leakage of electrolytebetween the adjacent frames 10 and 20.

During the operation of the cell shown in FIG. 1, the brine contained inthe tank is introduced into the lower part of the elementary cells 1 byapertures 21 and pipes 19. The anolyte is thus subjected to an ascendingmovement in the elementary cells 1, which facilitates the evacuation ofthe chlorine discharged at the anodes 12. The anolyte entrained by thechlorine falls back into the tank at the outlet from the tubes 23.

The use of insulating pipes 19 which extend approximately over theentire height of the elementary cells 1 for the purpose of connectingthese cells to the tank for electrolyte has the effect of reducing to avery low figure the electric current which is branched off by theelectrolyte contained in the tank.

In a particular variant, not shown in the drawing, of the electrolyserof FIG. 1, the whole of the tubes 23 for the evacuation of chlorine isreplaced by a single duct fixed to the partition 6 and emerging abovethe level of the electrolyte under the lid 7.

In a modified form of embodiment not shown in the drawing of theelectrolyser according to the invention, the pipes 19 mentioned aboveare replaced by flexible tubes arranged outside the electrolyser andleading out on the one hand near the bottom 22 of the elementary cells 1and on the other hand into the electrolyte tank. These tubes may also bearranged inside the cell and be made of a material which is anon-conductor for electricity.

The electrolyser which has just been described above may obviouslypresent numerous variant forms of embodiment without thereby fallingoutside the scope of the invention. For example all the elementary cellsmay, as a variant, be enclosed in a single case, the electrolyser beingno longer of the filter press type.

In FIGS. 4, 5 and 6 a modified form of embodiment of the electrolyser ofthe filter press type of FIGS. 1 to 3 is shown.

In the electrolyser of FIGS. 4 to 6, the frame 10 and the frame 20 ofeach elementary cell 1 are each drilled with two tubular sections 24 and25 (FIG. 6). The tubular sections 24 of the adjacent frames are in theextension of one another, as is the case with the tubular sections 25,so as to form two collectors 24' and 25' (FIG. 4).

The collector 24' is intended for the evacuation of the caustic solutionfrom each of the elementary cells 1. For this purpose the tubularsection 24 of the frame 10 of each cell 1 communicates with the cathodechamber 14 of this cell via an evacuation duct 26 made of insulatingmaterial, and extending to the interior of the cell 1 and leading outnear the bottom of same. This evacuation duct 26 is bent back on itselfso as to have a sufficient length to avoid a gross short-circuit of theelementary cells I by the caustic alkali.

The collector 25 is intended for the evacuation of the hydrogen givenoff at the cathodes of the elementary cells 1. For this purpose thetubular section 25 of the frame 10 of each cell 1 communicates with theupper part of the cathode chamber 14 of this cell 1, via an evacuationduct 27 extending to the interior of the chamber 14 and leading out nearto the upper end of the latter.

As a variant, a pipe 28 (FIG. 4) may be provided for feeding in areagent (for example CO: or a solution of NaHCO into the elementarycells 1. This pipe 28 is advantageously formed according to theinvention by the juxtaposition of tubular sections 28 drilled throughthe frames and 20 of the elementary cells 1. The tubular section 28 ofthe frame 10 of each cell 1 communicates with a pipe 29 of insulatingmaterial extending to the interior of the cathode chamber 14 and leadingout into a transverse distributor 30 for distributing the reagent in theupper zone of the chamber 14.

Although it is advantageous from the point of view of space required, toarrange the collectors 24' and 25' and the pipe 28' in the middle zoneof the cell, below the bottom 22 of the cathode chamber 14 and the anodechamber 15, these collectors and this pipe may if desired be arranged inanother zone of frames 10 and 20.

The tank for the electrolyte and the means for feeding the electrolyteto the cells and for evacuating the chlorine in the electrolyser ofFIGS. 4 to 6 is the same as in FIGS. 1 to 3.

FIG. 7 shows the upper part of a particular form of embodiment of theframe 10 surrounding the cathode chamber 14 of an elementary cell 1.

The frame 10 represented in FIG. 7 is formed with an aperture 31 in itsupper part. This aperture 31 is bounded at the top by a curved wall 32and at the bottom by a wall 33 which extends above the electrodes 1 1and 12 of the cell 1 and bounds the cathode chamber 14 of the cell. Thelateral wall of the frame 10 is drilled with two ducts, not shown in thedrawing, one of which opens into the upper part of the cathode chamberand is intended for the evacuation of the hydrogen produced in thecathode chamber 14 and the other of which opens into the lower part ofthe cathode chamber and is intended for the evacuation of the causticalkali also produced in the chamber 14.

FIG. 8 shows the upper part of the frame 20 corresponding to the frame10 of the FIG. 7. This frame 20 surrounds the anode chamber of theelementary cell 1. It is drilled in its upper part with an aperture 34corresponding to the above-mentioned aperture 31 of the frame 10. Thisaperture 34 is bounded at the top by a curved wall 35 and at the bottomby a wall 36 which correspond respectively to the walls 32 and 33 of theframe 10 of FIG. 7. The wall 36 bounds the anode chamber 15 of theelementary cell. It is drilled with an aperture 37 for the evacuation ofthe chlorine produced in the anode chamber 15. This aperture 37 isprolonged by a tube 23 which extends upwards in the aperture 34underneath the wall 35.

[n the electrolyser of the filter press type, the whole of the walls 32and 35 justaposed forms the lid 7 as above-mentioned of the cell, whilstthe whole of the walls 33 and 36 juxtaposed constitutes the bottom ofthe above-mentioned tank containing the electrolyte. The walls 33 and 36are formed of or covered with insulating material to avoid shortcircuiting through the brine in the tank formed by the openings 31 and34. As in the embodiments previously described, a separate feed duct(not shown) of insulating material leads from the bottom of theelectrolyte tank to the bottom of each of the cells. Such duct may beformed in the wall of the duct or as a separate tube. The end walls ofthis tank are formed by above-mentioned end elements 2 and 3 which arenot drilled with apertures like 31 and 34.

The wall 32 or 35 of at least one of the frame sets 10 or is drilledwith an orifice for the admission of elec- 6 trolyte into the tank.FUrthermore, the upper part of the wall 32 or 35 of at least one of thesets of frames 10 or 20 is drilled with an orifice for the evacuation ofchlorine coming from tubes 23, these tubes 23 leading out above thelevel of the electrolyte in the tank bounded underneath the walls 32 and35.

One of the frames 10 or 20 may also have its curved wall 32 or 35drilled with an aperture for connecting a level indicator tube similarto the tube 9 of FIGS. 1 and 4.

The walls 32 and 35 of the frames of FIGS. 7 and 8 may obviously have adifferent contour from a curved contour. They may, for example, have arectangular or trapezoidal contour.

The present invention is obviously not restricted to the forms ofembodiment described above. Numerous modifications may be made thereinwithout thereby falling outside the scope of he following claims.

What I claim and desire to secure by Letters Patent 1. A bipolar filterpress type diaphragm electrolyser for the production of chlorine,hydrogen and caustic alkali by the electrolysis of a solution of analkali metal chloride, said electrolyser comprising:

a. a plurality of vertical elementary cells disposed face-to-face,connected in series and each having an anode, a cathode, a diaphragmbetween said anode and cathode and at least one peripheral frame made ofinsulating material and having openings through the upper part thereof;

b. means defining a tank above said cells for holding said solutioncomprising a partition tightly overlying all the frames and insulatedfrom the latter and having holes and apertures therein, and a lidtightly fitted over said partition;

. means for feeding said solution to said tank;

. means for supplying said solution from said tank to said cells, saidmeans including channels in said frames opening at one end inside saidtank through said holes provided in the partition and opening at theother end in the respective cells through a bottom portion thereof,whereby the electric current by-passed through said solution in saidtank is limited;

means for evacuating chlorine out of the cells, said means includingsaid openings provided through the upper part of the frames, saidapertures provided through the partition and registering with saidopenings and at least one duct attached to the partition and disposedabout said apertures and extending upward from said partition andbeneath the lid; and

f. means for evacuating hydrogen and caustic alkali out of the cells,each of said cells having at least one peripheral frame having anopening through a bottom portion thereof, and said means for evacuatingcaustic alkali out of the cells comprising, for each cell, a U-shapedtube of insulating material which extends upward into the cell, doublesback on itself and opens at one end in a bottom portion of the cell, andat the other end in said opening provided through the bottom of theperipheral frame of the cell, the openings of all the peripheral framesof the cells registering to form a duct for the caustic alkali.

2. A diaphragm electrolyser for the production of chlorine, hydrogen andcaustic alkali by the electrolysis of a solution of an alkali metal,said electrolyser comprising:

a. a plurality of vertical elementary cells each having an anode, acathode and a diaphragm between said anode and cathode, said cells beingdisposed faceto-face and being connected in series;

b. means defining a tank above said cells for holding said solutioncomprising a partition overlying said cells and electrically insulatedfrom the latter and having apertures therein and a lid tightly fittedover said partition;

. means for feeding said solution to said tank; means for supplying saidsolution from said tank to said cells, said means including, for eachcell, a separate feed duct of insulating material extendingsubstantially over the whole height of the cell and opening at one endin the tank and opening at the other end in the cell through a bottomportion of the cell, whereby the electric current by-passed through saidsolution in said tank is limited;

. means for evacuating chlorine out of the cells, said means including,said apertures provided through the partition and communicating with thecells and at least one duct attached to the partition and disposed aboutsaid apertures and extending upward from said partition and beneath thelid; and

. means for evacuating hydrogen and caustic alkali 3. A diaphragmelectrolyser for the production of chlorine, hydrogen and caustic alkaliby the electrolysis of a solution of an alkali metal, said electrolysercomprising:

a. a plurality of vertical elementary cells each having an anode, acathode and a diaphragm between said anode and cathode, said cells beingdisposed faceto-face and being connected in series;

b. means defining a tank above said cells for holding said solutioncomprising a partition overlying said cells and electrically insulatedfrom the latter and having apertures therein and a lid tightly fittedover said partition;

c. means for feeding said solution to said tank;

d. means for supplying said solution from said tank to said cells, saidmeans including, for each cell, a separate feed duct of insulatingmaterial extending substantially over the whole height of the cell andopening at one end in the tank and opening at the other end in the cellthrough a bottom portion of the cell, whereby the electric currentby-passed through said solution in said tank is limited;

e. means for evacuating chlorine out of the cells, said means including,said apertures provided through the partition and communicating with thecells and at least one duct attached to the partition and disposed aboutsaid apertures and extending upward from said partition and beneath thelid; and

f. means for evacuating hydrogen and caustic alkali out of the cells,each of said cells having a transverse distributor and having at leastone peripheral frame having an opening through a bottom portion thereof,means for supplying a reagent to the cells, said reagent supplying meanscomprising, for each cell, a tube which extends upward in the cell, andwhich opens, at its upper end, in the transverse distributor inside thecell and, at its lower end, in the opening provided through the bottomof the peripheral frame of the cell, the openings of all the peripheralframes of the cells registering to form a duct for the reagent.

1. A BIPOLAR FILTER PRESS TYPE DIAPHRAGM ELECTROLYSER FOR THE PRODUCTIONOF CHLORINE, HYDROGEN AND CAUSTIC ALKALI BY THE ELECTROLYSIS OF ASOLUTION OF AN ALKALI METAL CHLORIDE, SAID ELECTROLYSER COMPRISING: A. APLURALITY OF VERTICAL ELEMENTARY CELLS DISPOSED FACE-TOFACE, CONNECTEDIN SERIES AND EACH HAVING AN ANODE, A CATHODE, A DIAPHRAGM BETWEEN SAIDANODE AND CATHODE AND AT LEAST ONE PERIPHERAL FRAME MADE OF INSULTINGMATERIAL AND HAVING OPENINGS THROUGH THE UPPER PART THEREOF. B. MEANSDEFINING A TANK ABOVE SAID CELLS FOR HOLDING SAID SOLUTION COMPRISING APARTITION TIGHTLY OVERLYING ALL THE FRAMES AND INSULATED FROM THE LATTERAND HAVING HOLES AND APERTURES THEREIN, AND A LID TIGHTLY FITTED OVERSAID PARTITION; C. MEANS FOR FEEDING SAID SOLUTION TO SAID TANK; D.MEANS FOR SUPPLYING SAID SOLUTION FROM SAID TANK TO SAID CELLS, SAIDMEANS INCLUDING CHANNELS TO SAID FRAMES OPENING AT ONE END INSIDE SAIDTANK THROUGH SAID HOLES PROVIDED IN THE PARTITION AND OPENING AT THEOTHER END IN THE RESPECTIVE CELLS THROUGH A BOTTOM PORTION THEREOF,WHEREBY THE ELECTRIC CURRENT BY-PASSED THROUGH SAID SOLUTION IN SAIDTANK IS LIMITED; E. MEANS FOR EVACUATING CHLORINE OUT OF THE CELLSS,SAID MEANS INCLUDING SAID OPNEINGS PROVIDED THROUGH THE UPPER PART
 2. ADIAPHRAGM ELECTROLYSER FOR THE PRODUCTION OF CHLORINE, HYDROGEN ANDCAUSTIC ALKALI BY THE ELECTROLYSIS OF A SOLUTION OF AN ALKALI METAL,SAID ELECTROLYSER COMPRISING: A. A PLURALITY OF VERTICAL ELEMENTARYCELLS EACH HAVING AN ANODE, A CATHODE AND A DIAPHRAGM BETWEEN SAID ANODEAND CATHODE, SAID CELLS BEING DISPOSED FACE-TO-FACE AND BEING CONNECTEDIN SERIES; B. MEANS DEFINING A TANK ABOVE SAID CELLS FOR HOLDING SAIDSOLUTION COMPRISING A PARTITION OVERLYING SAID CELLS AND ELECTRICALLYINSULATED FROM THE LATTER AND HAVING APERTURES THEREIN AND A LID TIGHTLYFITTED OVER SAID PARTITION, C. MEANS FOR FEEDING SAID SOLUTION TO SAIDTANK; D. MEANS FOR SUPPLYING SAID SOLUTION FROM SAID TANK TO SAID CELLS,SAID MEANS INCLUDING, FOR EACH CELL, A SEPARATE FEED DUCT OF IINSULATINGMATERIAL EXTENDING SUBSTANTIALLY OVER THE WHOLE HEIGHT OF THE CELL ANDOPENING AT ONE END IN THE TANK AND OPENING AT THE OTHER END IN THE CELLTHROUGH A BOTTOM PORTION OF THE CELL, WHEREBY THE ELECTRIC CURRENTBY-PASSED THROUGH SAID SOLUTION IN AID TANK IS LIMITED; E. MEANS FOREVACUATING CHLORINE OUT OF THE CELLS, SAID MEANS INCLUDING, SAIDAPERTURES PROVIDED THROUGH THE PARTITIONS AND COMMUNICATING WITH THECELLS AND AT LEAST ONE DUCT ATTACHED TO THE PARTITION AND DISPOSED ABOUTSAID APERTURES AND EXTENDIING UPWARD FROM SAID PARTITION AND BENEATH THELID; AND F. MEANS FOR EVACUATING HYDROGEN AND CAUSTIC ALKALI OUT OF THECELLS COMPRISING, FOR EACH CELL, A TUBE EXTENDING UPFRAME EACH HAVING ANOPENING THROUGH A BOTTOM PORTION THEREOF, AND SAID MEANS FOR EVACUATINGHYDROGEN OUT OF THE CELLS COMPRISING, FOR EACH CELL, A TUBE EXTENDINGUPWARD INTO THE CELL AND OPENING, AT ONE END, THE UPPER PART OF THE CELLAND, AT THE OTHER END, IN SAID OPENING PROVIDED THROUGH THE BOTTOM OFTHE PERIPHERAL FRAME OF THE CELL, THE OPENINGS OF ALL THE PERIPHERALFRAMES OF THE CELLS REGISTERING TO FORM A DUCT FOR THE HYDROGEN.
 3. Adiaphragm electrolyser for the production of chlorine, hydrogen andcaustic alkali by the electrolysis of a solution of an alkali metal,said electrolyser comprising: a. a plurality of vertical elementarycells each having an anode, a cathode and a diaphragm between said anodeand cathode, said cells being disposed face-to-face and being connectedin series; b. means defining a tank above said cells for holding saidsolution comprising a partition overlying said cells and electricallyinsulated from the latter and having apertures therein and a lid tightlyfitted over said partition; c. means for feeding said solution to saidtank; d. means for supplying said solution from said tank to said cells,said means including, for each cell, a separate feed duct of insulatingmaterial extending substantially over the whole height of the cell andopening at one end in the tank and opening at the other end in the cellthrough a bottom portion of the cell, whereby the electric currentby-passed through said solution in said tank is limited; e. means forevacuating chlorine out of the cells, said means including, saidapertures provided through the partition and communicating with thecells and at least one duct attached to the partition and disposed aboutsaid apertures and extending upward from said partition and beneath thelid; and f. means for evacuating hydrogen and caustic alkali out of thecells, each of said cells having a transverse distributor and having atleast one peripheral frame having an opening through a bottom portionthereof, means for supplying a reagent to the cells, said reagentsupplying means comprising, for each cell, a tube which extends upwardin the cell, and which opens, at its upper end, in the transversedistributor inside the cell and, at its lower end, in the openingprovided through the bottom of the peripheral frame of the cell, theopenings of all the peripheral frames of the cells registering to form aduct for the reagent.